Database Reference
In-Depth Information
Chapter 15. Reporting and Analysis
A database excels at keeping track of things—itsy bitsy, teeny tiny details about hundreds,
thousands, even millions of little things. But people aren't so good at dealing with all that de-
tail (hence the invention of the database). They like to see the
big picture
. If you want to un-
derstand your customers' music tastes, then a report of 200,000 individual MP3 sales doesn't
do you much good: The information is in there somewhere, but a feeble human brain stands
no chance of ferreting it out. A report that divides that information into 25
music genres
,
each with sales totals, both in aggregate and by gender, would help you interpret all those
reams of data at a glance. In other words, a well-designed report like the one you saw on
Creating a Dynamic Report with the Assistant
,
summarizes
the data for you. FileMaker's not
only fantastic at showing you information, it also excels at helping you see what it all
means
.
Summary Fields and Subsummary Parts
The very cornerstone of high-level analysis in FileMaker Pro is the summary report. To boil
the values in a set of records down to totals, averages, or one of several other aggregate
measures, the Summary Field is your tool. But hand in hand with the Summary Field are the
Subsummary and Grand Summary layout parts. A single Summary Field placed on a single
Subsummary layout part can, for example, form a report that displays one line for each city
that appears in your address book database and a count of how many of your contacts live in
that city.
NOTE
Sample files for the exercises in this chapter can be downloaded from this topic's Missing CD page
Summary Fields
A summary field doesn't hold one value per record like the other field types. Instead, sum-
mary fields gather up and process data from several records. Creating summary fields is
much easier than describing what they do, as you can see from the following example:
1.
In the People database, choose File
→
Manage
→
Database
.
You're about to add a field that counts the people in your database. This action is one
of the most common ways to summarize database information.
